CAIRO, Egypt -- During the six turbulent years since Rafik Hariri was blown up on the Beirut waterfront, supporters of the outspoken billionaire former prime minister longed for the day that his killers would face justice.

But the indictments submitted this week by the UN-mandated Special Tribunal for Lebanon hit with more splutter than splash. In the short term, Hezbollah will face minimal fallout from the charges against two of its officials, which the Tribunal named as ringleaders in the assassination.

The more serious threats to Hezbollah's primacy in the long run lie elsewhere. The first comes from the Tribunal, which will exert leverage over Lebanon not by the suspects it indicts but by the strength of the case it presents. The second and perhaps more important challenge to Hezbollah stems from the radical political changes sweeping the Arab world, which threaten its Syrian government sponsors in Damascus, and have put Hezbollah in the position of siding with authoritarian dictators in the era of the Arab spring.

First, consider the indictments. Leaks from the tribunal have made clear for years that Hezbollah operatives would be charged with the Hariri killing, and have even detailed much of the evidence, including mobile phone records that allegedly place a Hezbollah hit team around Hariri all the way to the moment of his death.

This ample warning has allowed Hezbollah to prepare strategically for this juncture. The Party of God convinced its own followers that Israel was behind the assassination, and more importantly, successfully cast doubt on the Tribunal's credibility even among Lebanese who don't support Hezbollah. It had help in this effort from the tribunal itself, hobbled by excessive leaks, its reliance on witnesses later proven to have fabricated their stories, and the seemingly political about-face in which it initially pinned the murder on Syria but later shifted its focus to Hezbollah.

For insurance, however, Hezbollah in January used its seats in parliament to topple the coalition government led by Saad Hariri, the slain leader's son, and replace him with another Sunni billionaire, Najib Mikati, who would be more amenable to Hezbollah's Islamic resistance agenda and less eager to cooperate with the Special Tribunal for Lebanon.

So when two top Hezbollah members were named in the indictment on June 30, the party didn't even feel the need to respond. Hassan Nasrallah, the supreme leader of Hezbollah, didn't even bother to address the Tribunal in his last speech before the imminent indictments, so confident was he in his party's ability to weather them.

The real impact of the indictments comes next. If the Lebanese government really does move to arrest the Hezbollah operatives, as the interior minister promised, it would provoke a showdown with Hezbollah from which the Party of God could emerge damaged. And once the detailed charges are released, if the Tribunal tells a compelling story of Hezbollah complicity, it could turn around the Robin Hood narrative that Hezbollah so successfully has woven for itself.

The broader context is crucial. Hezbollah has thrived in large measure because it has sewn up the undivided allegiance of its Lebanese constituents, who number a million or more, and has forged a much more enduring set of alliances with other sects than its political competitors. It also can count on the unalloyed support of Iran and Syria, which, along with Hamas, it touts as the Middle East's Axis of Resistance.

All this made a fine sell a year ago, when Israel and the U.S. were viewed as the lone bullies in the region and Hezbollah spoke for a disenfranchised Arab public.

Today, that equation has been rewritten. Across the Arab world, popular and legitimate movements have arisen to represent the deep public anger and profound aspiration for change. Dictators like Syria's Bashar al-Assad and his colleagues in Jordan, Bahrain, and Yemen have drawn opprobrium, and are now seen in many quarters of the Arab world as another problem, rather than an asset in the struggle against Israeli and U.S. hegemony. Many of these movements share Hezbollah's sympathy for the Palestinian cause, but not for its method of armed resistance and militant, authoritarian politics.

Hezbollah applauded when these movements toppled dictators in Egypt and Tunisia -- dictators who just happened to not share Hezbollah's agenda. But the Party of God, uncomfortably for its long-term legitimacy, has sided with the brutal regimes who are its patrons, in Syria and Iran, when popular movements in those countries called for change. This particular circle will be hard for Hezbollah to square.

If Syrian president Bashar Assad somehow survives with his grip on power intact, Hezbollah might be able to shrug off the indictments. Its operatives could go underground for years, and if the court tries Hezbollah officials in absentia the Party of God would dismiss it as a political show.

But if the Arab world continues its trajectory toward greater political openness, Hezbollah could discover itself in a bind. It might find its access to the deep pockets in Damascus curtailed. It certainly will face challenges to its political primacy that it never has before. Until now, Hezbollah could present itself as the lone Arab voice willing to criticize Israel and the United States, and thus, could justify all its tactics and ideology.

However, the Arab spring has sown movements willing to defy American and Israeli policy without advocating endless war or a religious state. They are likely to steal much of Hezbollah's thunder.

More than any indictment, this groundswell could reverse Hezbollah's fortunes.